Tag: bbc master

As promised in an earlier post, here’s the low down on my retro 8bit pride and joy; my BBC Master!

The BBC Master 128K, the bigger, badder brother of the BBC Micro computer – a real beast of a (8bit) machine! And this one is mine, all mine! mwahahaha….

Now, back in the day this machine’s specs were impressive indeed… it boasted 128Kb of RAM (compared to the 32Kb of the BBC Micro). Now Acorn had an interesting approach to memory. The Master didn’t have 128Kb of RAM like you’d think of it today, oh no… It still had 32Kb of ‘main’ RAM (like the Micro) however the Master also had 20Kb of dedicated video RAM, 12Kb of ‘OS workspace’ RAM and 64Kb of ‘sideways’ RAM. It’s processor was a whopping 2Mhz 6502 based chip, it also had 4 channel sound and 8 different graphics modes (including the famous ‘teletext’ mode).

All in all, far superior in many ways to the old Micro. However advanced it was, it had some problems running software and games that had been designed for the Micro due to the way that some programs had been written (using illegal opcodes or addressing hardware directly for instance). Not the end of the world, but a bit frustrating.

Here we see the innards of my BBC Master.

This machine I purchased, fully reburbised from Retroclinic as I’d decided that after the tinkering I’d had to do with the hardware to get my old Micro working I’d quite like to get a head-start with the Master. Also the one of the reason’s I went to Retroclinc was because this Master had been outfitted with a Compact Flash memory card acting as an internal Hard Drive.

A BBC Master with a Hard drive! A whopping 512Mb of storage space. Needless to say this is going to take some time to fill up!

I’ve also fitted an additional upgrade – an updated version of the Operarting System (MOS3.5 instead of MOS3.2) which provides a number of benefits (one of which is that the clock works post year 2000!). However should, for some reason, I need to switch back to MOS3.2 there’s a handy switch which will alter a circuit on the PCB that’s holding the OS chip and revert it to the MOS3.2 ROM image. Funky.

So, there we have it! It’s made of awesome, I love it!

But i’ve already decided on the next upgrade I’m getting for it… USB expansions! Oh yes. Bringing the BBC Master screaming into the modern computer world, that clever chap Mark at Retroclinic has gone and done it again and created the DataCentre! I’m going to save the pennies for that, oh yes!